Improvement in electrical linings for safes, vaults



Wiiinii/i 3i GUERNSEY.

inigninvsmen. in Eiecficai Lining for Sa" s, iv/nuits, ic.

Patented Aprii 30, i872.

Figi.

WiTN ESSES. KQ/Muni@ '.TNTTED STATES PATENT OFFICE.

WILLIAM B. GUERNSEY, OF JERSEY CITY, NEW JERSEY. l

Specification forming part of Letters Patent No. 126,289, dated April 30, 1872.

Specilication ot' an Improved Electrical Protectin g Screen or Lining for Safes, Vaults, Sie., invented by WILLIAM B. GUERNSEY, of Jersey City, in the county of Hudson, State of New Jersey.

The purpose of this invention is to enable a screen or lining of electrical conductors to be so made that attempts to penetrate it to any damaging extent must necessarily result in the breaking of the electrical circuit, or in a cross-connecting ot' two circuits to the same effect as it' either or both were broken. I effeet this by using for such conductors stripes of metal foil, superimposed upon wood or other suitable material by (preferably) such means as are used by painters and gilders in ornamentation. As these stripes can be reached only by piercing the Wood or base upon which they are made, it becomes practically impossible to tamper with them, as could be done with wires or with sheets of foil, as heretofore used. They will be surely broken by any attempt to make a metallic connection upon them from the outside. By tirst placing a coating of some hard but brittle material like plaster, upon the wood, and then making the stripe upon such coating, the difiiculty ot' tampering with such conductors is greatly increased.

Figure l is a view of the interior of one-halt of a screen (or cabinet) designed for the protection of safes. Fig. 2 is-a plan view ot' same arrangement showing saie in its place.

The stripes of metal foil (t a a., Ste., are here shown as being mere parallel bands; but their shape, width, or proximity are mere matters of detail to be determined by judgment and experience. So, also, a stripe may be made, instead ot' as here shown, in a continuous length or coil surrounding the whole inside of the cabinet,77 and returning again and again upon itself, having no or but few joinings, and only two free ends, or may be arranged in other manners; but in the iigure the stripes are shown. as having been made in sections, each section embracing some component part ot' the cabinet, as a side or a top, and each end ot each stripe terminating in a short length of copper wire, which is embedded in or connected with the stripe by a broad-headed screw or nail, except that some of the said stripes are connected to springs or metallic contact pieces b b b b, placed in the joinings of such sections, so that when the cabinet is together it cannot be taken apart without breaking a circuit, which might otherwise be closed. When the cabinet is put together the foil ends ofthe wires c c c c are to be attached in either a regular or confused manner, so as to bring each stripe into the circuit or into a circuit-perhaps into one ofthe two parts of a circuit, which parts are so related to each other that the cross-connecting ot' them shall produce the same effect as the severing of them.

I do not claim the use of sheet metal or metallic ribbons in the construction of electric protecting envelopes for safes, as I am aware 

